TY - JOUR
T1 - Morphological identification of ticks and molecular detection of tick-borne pathogens from bare-nosed wombats (Vombatus ursinus)
AU - Beard, Danielle
AU - Stannard, Hayley J.
AU - Old, Julie M.
N1 - Funding Information:
Thank you to Amanda Cox, Danie Ondinea, Bronlow Hall, Inga Schwaiger, Belinda Goldsworthy, Lyn Oberon, Diane Hinton, Liesl Perryman, Elena Guarracino, Pru Carpenter and Deborah Kerr for assisting with tick collection, and Siobhon Egan for assisting with tick identification. Donations to Wombat Giving available through the WomSAT website funded this project.
Publisher Copyright:
© 2021, The Author(s).
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/12
Y1 - 2021/12
N2 - BackgroundTicks
are obligate haematophagous ectoparasites of vertebrate hosts and
transmit the widest range of pathogenic organisms of any arthropod
vector. Seven tick species are known to feed on bare-nosed wombats (Vombatus ursinus), in addition to the highly prevalent Sarcoptes scabiei
mite which causes fatal sarcoptic mange in most bare-nosed wombat
populations. Little is known about the pathogens carried by most wombat
ticks or how they may impact wombats and wombat handlers.MethodsWombat
ticks were sourced from wildlife hospitals and sanctuaries across
Australia and identified to species level using taxonomic keys. Genomic
DNA was extracted from a subsample, and following the amplification of
the bacterial 16S rRNA gene V3–V4 hypervariable region, next-generation
sequencing (NGS) on the Illumina MiSeq platform was used to assess the
microbial composition.ResultsA
total of 447 tick specimens were collected from 47 bare-nosed wombats
between January 2019 and January 2020. Five species of ticks were
identified comprising wombat tick Bothriocroton auruginans (n = 420), wallaby tick Haemaphysalis bancrofti (n = 8), bush tick Haemaphysalis longicornis (n = 3), common marsupial tick Ixodes tasmani (n = 12), and Australian paralysis tick Ixodes holocyclus (n
= 4). Tick infestations ranged from one to 73 ticks per wombat. The
wombat tick was the most prevalent tick species comprising 94% of the
total number of samples and was present on 97.9% (46/47) of wombat
hosts. NGS results revealed the 16S rRNA gene diversity profile was
predominantly Proteobacteria (55.1%) followed by Firmicutes (21.9%) and
Actinobacteria (18.4%). A species of Coxiella sharing closest sequence identity to Coxiella burnetii (99.07%), was detected in 72% of B. auruginans and a Rickettsiella endosymbiont dominated the bacterial profile for I. tasmani.ConclusionsA new host record for H. longicornis
is the bare-nosed wombat. One adult male and two engorged adult female
specimens were found on an adult male wombat from Coolagolite in New
South Wales, and more specimens should be collected to confirm this host
record. The most prevalent tick found on bare-nosed wombats was B. auruginans,
confirming previous records. Analysis of alpha-diversity showed high
variability across both sample locations and instars, similar to
previous studies. The detection of various Proteobacteria in this study
highlights the high bacterial diversity in native Australian ticks.
AB - BackgroundTicks
are obligate haematophagous ectoparasites of vertebrate hosts and
transmit the widest range of pathogenic organisms of any arthropod
vector. Seven tick species are known to feed on bare-nosed wombats (Vombatus ursinus), in addition to the highly prevalent Sarcoptes scabiei
mite which causes fatal sarcoptic mange in most bare-nosed wombat
populations. Little is known about the pathogens carried by most wombat
ticks or how they may impact wombats and wombat handlers.MethodsWombat
ticks were sourced from wildlife hospitals and sanctuaries across
Australia and identified to species level using taxonomic keys. Genomic
DNA was extracted from a subsample, and following the amplification of
the bacterial 16S rRNA gene V3–V4 hypervariable region, next-generation
sequencing (NGS) on the Illumina MiSeq platform was used to assess the
microbial composition.ResultsA
total of 447 tick specimens were collected from 47 bare-nosed wombats
between January 2019 and January 2020. Five species of ticks were
identified comprising wombat tick Bothriocroton auruginans (n = 420), wallaby tick Haemaphysalis bancrofti (n = 8), bush tick Haemaphysalis longicornis (n = 3), common marsupial tick Ixodes tasmani (n = 12), and Australian paralysis tick Ixodes holocyclus (n
= 4). Tick infestations ranged from one to 73 ticks per wombat. The
wombat tick was the most prevalent tick species comprising 94% of the
total number of samples and was present on 97.9% (46/47) of wombat
hosts. NGS results revealed the 16S rRNA gene diversity profile was
predominantly Proteobacteria (55.1%) followed by Firmicutes (21.9%) and
Actinobacteria (18.4%). A species of Coxiella sharing closest sequence identity to Coxiella burnetii (99.07%), was detected in 72% of B. auruginans and a Rickettsiella endosymbiont dominated the bacterial profile for I. tasmani.ConclusionsA new host record for H. longicornis
is the bare-nosed wombat. One adult male and two engorged adult female
specimens were found on an adult male wombat from Coolagolite in New
South Wales, and more specimens should be collected to confirm this host
record. The most prevalent tick found on bare-nosed wombats was B. auruginans,
confirming previous records. Analysis of alpha-diversity showed high
variability across both sample locations and instars, similar to
previous studies. The detection of various Proteobacteria in this study
highlights the high bacterial diversity in native Australian ticks.
KW - 16S ribosomal RNA gene
KW - Bacteria
KW - Marsupial
KW - Microbiome
KW - Next-generation sequencing
KW - Tick
KW - Wombat
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U2 - 10.1186/s13071-020-04565-6
DO - 10.1186/s13071-020-04565-6
M3 - Article
C2 - 33468211
AN - SCOPUS:85100116196
VL - 14
JO - Parasites and Vectors
JF - Parasites and Vectors
SN - 1756-3305
M1 - 60
ER -